Development and use of an experimental device including a laser scanning vibrometer for measuring the vibration transmissibility mapping on the dorsum of hands gripping a vibrating handle.

Many experimental studies have been carried out by different research laboratories in order to assess the biodynamic response of the upper limb exposed to vibrations.1 Indeed, this response provides a way to characterise the changes of the mechanical stress and strain field occurring during the propagation of vibration and it has been suggested that such modifications are likely to be responsible for the onset of hand-arm vibration syndrome. Previous works succeeded in quantifying the influence of several factors like posture, push and grip forces on the dynamic response of Hand-Arm system. Most of these measurements like for example the driving point mechanical impedance, lead to evaluate the global behaviour of the upper limb. We propose in the following study to describe an original experimental device for assessing the acceleration by using a scanning vibrometer at selected points of a measuring mesh projected on the back of hand. Thus, we can estimate local dynamic responses, for instance expressed in terms of acceleration transmissibility maps and then extract more accurate information from the spatial characteristics of the vibration. Then, the method was implemented to analyse the effect of various parameters on the acceleration transfer between a vibrating handle and the back of hand. Push and grip forces, postures, ambient temperature, handle acceleration have been varied and the attenuation ability of antivibration glove materials have also been tested, but only a few findings will be presented in this paper.